Dear Mr. Vedha,
The main problem with the termites in the soil is that they attack the roots leading to tumbling of the plants resulting in mortality. Some plant species are susciptible to termite attack. There are several species that are termite resistant. If there is no mortality of the plants in the plantation it has to be inferred that the plants are termite resistant. Here in this case as per your post there is good growth of the banana plants despite the termites eating away the mulch. So long there is no mortality in banana plants and growing well as noticed in your farm there is no need for concern and you need not remove the mulch. Infact termites attacking the mulch of dead plants imroves the fertility of the soil.
Siva Sankara Reddy